scholarly journals Pontibacillus sp. ALD_SL1 and Psychroflexus sp. ALD_RP9, two novel moderately halophilic bacteria isolated from sediment and water from the Aldabra Atoll, Seychelles

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256639
Author(s):  
Avril J. E. von Hoyningen-Huene ◽  
Tabea J. Schlotthauer ◽  
Dominik Schneider ◽  
Anja Poehlein ◽  
Rolf Daniel
Keyword(s):  
Novel Species ◽  
Halophilic Bacteria ◽  
Mangrove Sediment ◽  
Bacterial Isolates ◽  
Anaerobic Conditions ◽  
Facultatively Anaerobic ◽  
Ph Tolerance ◽  
Nacl Concentration ◽  
Ph Conditions ◽  
Moderately Halophilic Bacteria

Pontibacillus sp. ALD_SL1 and Psychroflexus sp. ALD_RP9 are two novel bacterial isolates from mangrove sediment and a moderately hypersaline pool on the Aldabra Atoll, Seychelles. The isolates represent two novel species were characterised physiologically and genomically. Pontibacillus sp. ALD_SL1 is a facultatively anaerobic yellow, motile, rod-shaped Gram-positive, which grows optimally at a NaCl concentration of 11%, pH 7 and 28°C. It is the third facultatively anaerobic member of the genus Pontibacillus. The organism gains energy through the fermentation of pyruvate to acetate and ethanol under anaerobic conditions. The genome is the first among Pontibacillus that harbours a megaplasmid. Psychroflexus sp. ALD_RP9 is an aerobic heterotroph, which can generate energy by employing bacteriorhodopsins. It forms Gram-negative, orange, non-motile rods. The strain grows optimally at NaCl concentrations of 10%, pH 6.5–8 and 20°C. The Psychroflexus isolate tolerated pH conditions up to 10.5, which is the highest pH tolerance currently recorded for the genus. Psychroflexus sp. ALD_RP9 taxonomically belongs to the clade with the smallest genomes. Both isolates show extensive adaptations to their saline environments yet utilise different mechanisms to ensure survival.

Survival of extremely and moderately halophilic isolates of Tunisian solar salterns after UV-B or oxidative stress

2011 ◽  
Vol 57 (11) ◽  
pp. 923-933 ◽  
Author(s):  
Hana Trigui ◽  
Salma Masmoudi ◽  
Céline Brochier-Armanet ◽  
Sami Maalej ◽  
Sam Dukan
Keyword(s):  
Halophilic Bacteria ◽  
Halophilic Archaea ◽  
Oxygen Species ◽  
Solar Saltern ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Moderately Halophilic ◽  
Nacl Concentration ◽  
Extremely Halophilic Archaea ◽  
Moderately Halophilic Bacteria

Adaptation to a solar saltern environment requires mechanisms providing tolerance not only to salinity but also to UV radiation (UVR) and to reactive oxygen species (ROS). We cultivated prokaryote halophiles from two different salinity ponds: the concentrator M1 pond (240 g·L–1NaCl) and the crystallizer TS pond (380 g·L–1NaCl). We then estimated UV-B and hydrogen peroxide resistance according to the optimal salt concentration for growth of the isolates. We observed a higher biodiversity of bacterial isolates in M1 than in TS. All strains isolated from TS appeared to be extremely halophilic Archaea from the genus Halorubrum . Culturable strains isolated from M1 included extremely halophilic Archaea (genera Haloferax , Halobacterium , Haloterrigena , and Halorubrum) and moderately halophilic Bacteria (genera Halovibrio and Salicola ). We also found that archaeal strains were more resistant than bacterial strains to exposure to ROS and UV-B. All organisms tested were more resistant to UV-B exposure at the optimum NaCl concentration for their growth, which is not always the case for H2O2. Finally, if these results are extended to other prokaryotes present in a solar saltern, we could speculate that UVR has greater impact than ROS on the control of prokaryote biodiversity in a solar saltern.

scholarly journals Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov., moderately halophilic bacteria isolated from a deep-sea methane cold seep

2007 ◽  
Vol 57 (6) ◽  
pp. 1243-1249 ◽  
Author(s):  
Ngoc-Phuc Hua ◽  
Atsuko Kanekiyo ◽  
Katsunori Fujikura ◽  
Hisato Yasuda ◽  
Takeshi Naganuma
Keyword(s):  
Deep Sea ◽  
Sequence Similarity ◽  
Halophilic Bacteria ◽  
Cold Seep ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
High Sequence Similarity ◽  
Moderately Halophilic ◽  
Type Strains ◽  
Moderately Halophilic Bacteria

Two Gram-positive, rod-shaped, moderately halophilic bacteria were isolated from a deep-sea carbonate rock at a methane cold seep in Kuroshima Knoll, Japan. These bacteria, strains IS-Hb4T and IS-Hb7T, were spore-forming and non-motile. They were able to grow at temperatures as low as 9 °C and hydrostatic pressures up to 30 MPa. Based on high sequence similarity of their 16S rRNA genes to those of type strains of the genus Halobacillus, from 96.4 % (strain IS-Hb7T to Halobacillus halophilus NCIMB 9251T) to 99.4 % (strain IS-Hb4T to Halobacillus dabanensis D-8T), the strains were shown to belong to this genus. DNA–DNA relatedness values of 49.5 % and 1.0–33.0 %, respectively, were determined between strains IS-Hb4T and IS-Hb7T and between these strains and other Halobacillus type strains. Both strains showed the major menaquinone MK7 and l-orn–d-Asp cell-wall peptidoglycan type. Straight-chain C16 : 0, unsaturated C16 : 1 ω7c alcohol and C18 : 1 ω7c and cyclopropane C19 : 0 cyc fatty acids were predominant in both strains. The DNA G+C contents of IS-Hb4T and IS-Hb7T were respectively 43.3 and 42.1 mol%. Physiological and biochemical analyses combined with DNA–DNA hybridization results allowed us to place strains IS-Hb4T (=JCM 14154T=DSM 18394T) and IS-Hb7T (=JCM 14155T=DSM 18393T) in the genus Halobacillus as the respective type strains of the novel species Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov.

Isolation, Characterization and Application of Protease Enzyme from Marine Bacteria

2021 ◽  
pp. 4236-4240
Author(s):  
Sneha S ◽  
Mrunal Palsokar ◽  
Vemula Sai Jahnavi ◽  
Anwesha Sarkar ◽  
K. V. Bhaskara Rao
Keyword(s):  
Marine Bacteria ◽  
Peptide Bond ◽  
Mangrove Sediment ◽  
Bacillus Sp ◽  
Bacterial Isolates ◽  
Sediment Samples ◽  
Protease Enzyme ◽  
Stain Removal ◽  
Marine Sediment Sample ◽  
Protease Assay

Protease constitutes the major group of catalytic enzymes which is involved in hydrolyzing peptide bond of proteins. Marine sediment sample were collected and protease producing bacterial isolates were identified by using casein as a substrate. The organisms were characterized by biochemical test and identified as Bacillus sp. In order to check for the production of protease enzyme, quantitative protease assay and Lowry’s method of protein estimation was carried out. The crude extract of protease was subjected for blood stain removal activity and the enzyme proved to be efficient which removed the stain in 15 min. The purpose of the current study is to isolate, identify, characterize and to carry out applications of protease enzyme from marine bacteria isolated from mangrove sediment samples.

scholarly journals Exploring the hydrolytic potential of cultured halophilic bacteria isolated from the Atacama Desert

2019 ◽  
Vol 366 (17) ◽  
Author(s):  
Robert Ruginescu ◽  
Cristina Purcărea ◽  
Cristina Dorador ◽  
Paris Lavin ◽  
Roxana Cojoc ◽  
...  
Keyword(s):  
Halophilic Bacteria ◽  
Agar Plate ◽  
Atacama Desert ◽  
Industrial Processes ◽  
Biotechnological Applications ◽  
Bacterial Isolates ◽  
Salt Tolerant ◽  
Essential Step ◽  
Extremophilic Microorganisms ◽  
Biological Sources

ABSTRACT Considering that most industrial processes are carried out under harsh physicochemical conditions, which would inactivate enzymes from commonly isolated mesophilic organisms, current studies are geared toward the identification of extremophilic microorganisms producing enzymes resistant to extreme salt concentrations, temperature and pH. Among the extremophiles, halophilic microorganisms are an important source of salt-tolerant enzymes that can be used in varying biotechnological applications. In this context, the aim of the present work was to isolate and identify halophiles producing hydrolases from the Atacama Desert, one of the harshest environments on Earth. Isolates were recovered from halite samples and screened for the presence of seven different hydrolase activities (amylase, caseinase, gelatinase, lipase, pectinase, cellulase and inulinase) using agar plate-based assays. From a total of 23 halophilic bacterial isolates, most showed lipolytic (19 strains) and pectinolytic (11 strains) activities. The molecular identification of eight selected isolates showed a strong similarity to members of the Halomonas and Idiomarina genera. Therefore, the present study represents a preliminary, but essential, step to identify novel biological sources of extremozymes in an environment once thought to be devoid of life.

scholarly journals Growth and nitrogen removal characteristics of Halomonas sp. B01 under high salinity

2019 ◽  
Vol 69 (13) ◽  
pp. 1425-1433 ◽  
Author(s):  
Te Wang ◽  
Zhengzhong Jiang ◽  
Wenbo Dong ◽  
Xiaoya Liang ◽  
Linghua Zhang ◽  
...  
Keyword(s):  
Mrna Expression ◽  
High Salinity ◽  
Halophilic Bacteria ◽  
Compatible Solutes ◽  
Aerobic Denitrification ◽  
Protective Mechanism ◽  
Sod Activity ◽  
N Removal ◽  
Nacl Concentration ◽  
Expression Abundance

Abstract Purpose At present, the nitrogen (N) removal efficiency of the microbial treatment in the high-salinity nitrogenous wastewaters is relatively low. Study on the N removal behavior and properties of moderately halophilic bacteria Halomonas under high salinity is of great significance for the microbial treatment of high-salinity nitrogenous wastewater. Methods The response mechanism of Halomonas sp. B01 to high osmotic pressure stress was investigated by measuring the compatible solute ectoine concentration and superoxide dismutase (SOD) activity. The salt tolerance during growth and N removal of the strain was evaluated by measuring the activities of growth-related and N removal–related enzymes and the mRNA expression abundance of ammonia monooxygenase-encoding gene (amoA). The process of simultaneous heterotrophic nitrification and aerobic denitrification (SND) under high salinity was described by measuring the concentration of inorganic N. Result Halomonas sp. B01 synthesized ectoine under NaCl stress, and the intracellular ectoine concentration increased with increased NaCl concentration in the growth medium. When the NaCl concentration of the medium reached 120 g L−1, the malondialdehyde concentration and SOD activity were significantly increased to 576.1 μg mg−1 and 1.7 U mg−1, respectively. The growth-related and N removal–related enzymes of the strain were active or most active in medium with 30–60 g L−1 NaCl. The amoA of the strain cultured in medium with 60 g L−1 NaCl had the highest mRNA expression abundance. In the N removal medium containing 60 g L−1 NaCl and 2121 mg L−1 NH4+-N, SND by Halomonas sp. B01 was performed over 96 h and the N removal rate reached 98.8%. Conclusion In addition to the protective mechanism of synthetic compatible solutes, Halomonas sp. B01 had the repair mechanism of SOD for lipid peroxidation. The growth-related and N removal–related enzymes of the strain were most active at a certain salt concentration; amoA also had the highest mRNA expression abundance under high salinity. Halomonas sp. B01 could efficiently perform N removal by SND under high salinity.

scholarly journals Modestobacter versicolor sp. nov., an actinobacterium from biological soil crusts that produces melanins under oligotrophy, with emended descriptions of the genus Modestobacter and Modestobacter multiseptatus Mevs et al. 2000

2007 ◽  
Vol 57 (9) ◽  
pp. 2014-2020 ◽  
Author(s):  
Gundlapally S. N. Reddy ◽  
Ruth M. Potrafka ◽  
Ferran Garcia-Pichel
Keyword(s):  
Type Strain ◽  
Novel Species ◽  
Sequence Similarity ◽  
Diaminopimelic Acid ◽  
Rrna Gene ◽  
Respiratory Quinone ◽  
Total Pigment ◽  
Ph Tolerance ◽  
Major Respiratory Quinone ◽  
Polyphasic Characterization

A novel isolate, CP153-2T, was obtained from topsoil biological crusts in the Colorado Plateau (USA). Colonies were black in colour due to melanin-like pigments when grown on oligotrophic medium, but not when grown on copiotrophic medium. Induction of melanogenesis was independent of growth phase or illumination conditions, including exposure to UVB and UVA radiation, but exposure to UVB could enhance total pigment production and growth under low nitrogen prevented its synthesis. This mode of regulation was previously unknown among melanin-producing bacteria. Polyphasic characterization of the strain revealed that cells were short, straight to curved or irregular rods that developed into pairs and formed multiseptate short filaments, with rare bud-like cells. Short rods were typically motile by means of flagella; multicellular structures tended to be sessile. Cells stained Gram-positive, grew at 4–30 °C and had a narrow range of pH tolerance (pH 5–9). The major fatty acids were iso-C15:0 iso-C16 : 0, anteiso-C15 : 0 and C18 : 1; MK-9(H4) was the major respiratory quinone. Its peptidoglycan contained meso-diaminopimelic acid. Based on 16S rRNA gene sequence similarity data, its closest relative (98.1 % similarity) was Modestobacter multiseptatus DSM 44406T, which is similar morphologically. Based on the above characteristics, strain CP153-2T was also assigned to the genus Modestobacter. However, CP153-2T had a relatedness of only 49.9 % in whole-genome reassociation comparisons with the type strain of M. multiseptatus and thus formally represents a novel species, for which the name Modestobacter versicolor sp. nov. is proposed. Additional evidence in support of a novel species comes from phenotypic and chemotaxonomic characteristics. Strain CP153-2T (=ATCC BAA-1040T =DSM 16678T) is the type strain of M. versicolor.

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